"For instance, side deals, if there are any between Ricky Muir and Mr Palmer's party, so that in the event that the behaviour of this voting bloc leads to a double dissolution, what guarantees are there for Mr Muir's employment?"

Senator Xenophon says if Mr Palmer does not release the details of the MOU, he will introduce a private members bill to force the disclosure.

"And this is something that shouldn't apply simply to Mr Palmer and Mr Muir, it should apply to any political party or blocs or political parties that decide to get together unbeknownst to electors at the time of the election," he said.